drivers/char/drm/drm_memory.h

   1 /**
   2  * \file drm_memory.h
   3  * Memory management wrappers for DRM
   4  *
   5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
   6  * \author Gareth Hughes <gareth@valinux.com>
   7  */
   8
   9 /*
  10  * Created: Thu Feb  4 14:00:34 1999 by faith@valinux.com
  11  *
  12  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  13  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  14  * All Rights Reserved.
  15  *
  16  * Permission is hereby granted, free of charge, to any person obtaining a
  17  * copy of this software and associated documentation files (the "Software"),
  18  * to deal in the Software without restriction, including without limitation
  19  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  20  * and/or sell copies of the Software, and to permit persons to whom the
  21  * Software is furnished to do so, subject to the following conditions:
  22  *
  23  * The above copyright notice and this permission notice (including the next
  24  * paragraph) shall be included in all copies or substantial portions of the
  25  * Software.
  26  *
  27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  28  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  29  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  30  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  31  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  32  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  33  * OTHER DEALINGS IN THE SOFTWARE.
  34  */
  35
  36 #include <linux/config.h>
  37 #include <linux/highmem.h>
  38 #include <linux/vmalloc.h>
  39 #include "drmP.h"
  40
  41 /**
  42  * Cut down version of drm_memory_debug.h, which used to be called
  43  * drm_memory.h.
  44  */
  45
  46 #if __OS_HAS_AGP
  47
  48 #include <linux/vmalloc.h>
  49
  50 #ifdef HAVE_PAGE_AGP
  51 #include <asm/agp.h>
  52 #else
  53 # ifdef __powerpc__
  54 #  define PAGE_AGP      __pgprot(_PAGE_KERNEL | _PAGE_NO_CACHE)
  55 # else
  56 #  define PAGE_AGP      PAGE_KERNEL
  57 # endif
  58 #endif
  59
  60 /*
  61  * Find the drm_map that covers the range [offset, offset+size).
  62  */
  63 static inline drm_map_t *
  64 drm_lookup_map (unsigned long offset, unsigned long size, drm_device_t *dev)
  65 {
  66         struct list_head *list;
  67         drm_map_list_t *r_list;
  68         drm_map_t *map;
  69
  70         list_for_each(list, &dev->maplist->head) {
  71                 r_list = (drm_map_list_t *) list;
  72                 map = r_list->map;
  73                 if (!map)
  74                         continue;
  75                 if (map->offset <= offset && (offset + size) <= (map->offset + map->size))
  76                         return map;
  77         }
  78         return NULL;
  79 }
  80
  81 static inline void *
  82 agp_remap (unsigned long offset, unsigned long size, drm_device_t *dev)
  83 {
  84         unsigned long *phys_addr_map, i, num_pages = PAGE_ALIGN(size) / PAGE_SIZE;
  85         struct drm_agp_mem *agpmem;
  86         struct page **page_map;
  87         void *addr;
  88
  89         size = PAGE_ALIGN(size);
  90
  91 #ifdef __alpha__
  92         offset -= dev->hose->mem_space->start;
  93 #endif
  94
  95         for (agpmem = dev->agp->memory; agpmem; agpmem = agpmem->next)
  96                 if (agpmem->bound <= offset
  97                     && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >= (offset + size))
  98                         break;
  99         if (!agpmem)
 100                 return NULL;
 101
 102         /*
 103          * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
 104          * the CPU do not get remapped by the GART.  We fix this by using the kernel's
 105          * page-table instead (that's probably faster anyhow...).
 106          */
 107         /* note: use vmalloc() because num_pages could be large... */
 108         page_map = vmalloc(num_pages * sizeof(struct page *));
 109         if (!page_map)
 110                 return NULL;
 111
 112         phys_addr_map = agpmem->memory->memory + (offset - agpmem->bound) / PAGE_SIZE;
 113         for (i = 0; i < num_pages; ++i)
 114                 page_map[i] = pfn_to_page(phys_addr_map[i] >> PAGE_SHIFT);
 115         addr = vmap(page_map, num_pages, VM_IOREMAP, PAGE_AGP);
 116         vfree(page_map);
 117
 118         return addr;
 119 }
 120
 121 static inline unsigned long
 122 drm_follow_page (void *vaddr)
 123 {
 124         pgd_t *pgd = pgd_offset_k((unsigned long) vaddr);
 125         pud_t *pud = pud_offset(pgd, (unsigned long) vaddr);
 126         pmd_t *pmd = pmd_offset(pud, (unsigned long) vaddr);
 127         pte_t *ptep = pte_offset_kernel(pmd, (unsigned long) vaddr);
 128         return pte_pfn(*ptep) << PAGE_SHIFT;
 129 }
 130
 131 #else /* __OS_HAS_AGP */
 132
 133 static inline drm_map_t *drm_lookup_map(unsigned long offset, unsigned long size, drm_device_t *dev)
 134 {
 135   return NULL;
 136 }
 137
 138 static inline void *agp_remap(unsigned long offset, unsigned long size, drm_device_t *dev)
 139 {
 140   return NULL;
 141 }
 142
 143 static inline unsigned long drm_follow_page (void *vaddr)
 144 {
 145   return 0;
 146 }
 147
 148 #endif
 149
 150 static inline void *drm_ioremap(unsigned long offset, unsigned long size, drm_device_t *dev)
 151 {
 152         if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture) {
 153                 drm_map_t *map = drm_lookup_map(offset, size, dev);
 154
 155                 if (map && map->type == _DRM_AGP)
 156                         return agp_remap(offset, size, dev);
 157         }
 158         return ioremap(offset, size);
 159 }
 160
 161 static inline void *drm_ioremap_nocache(unsigned long offset, unsigned long size,
 162                                         drm_device_t *dev)
 163 {
 164         if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture) {
 165                 drm_map_t *map = drm_lookup_map(offset, size, dev);
 166
 167                 if (map && map->type == _DRM_AGP)
 168                         return agp_remap(offset, size, dev);
 169         }
 170         return ioremap_nocache(offset, size);
 171 }
 172
 173 static inline void drm_ioremapfree(void *pt, unsigned long size, drm_device_t *dev)
 174 {
 175         /*
 176          * This is a bit ugly.  It would be much cleaner if the DRM API would use separate
 177          * routines for handling mappings in the AGP space.  Hopefully this can be done in
 178          * a future revision of the interface...
 179          */
 180         if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture
 181             && ((unsigned long) pt >= VMALLOC_START && (unsigned long) pt < VMALLOC_END))
 182         {
 183                 unsigned long offset;
 184                 drm_map_t *map;
 185
 186                 offset = drm_follow_page(pt) | ((unsigned long) pt & ~PAGE_MASK);
 187                 map = drm_lookup_map(offset, size, dev);
 188                 if (map && map->type == _DRM_AGP) {
 189                         vunmap(pt);
 190                         return;
 191                 }
 192         }
 193
 194         iounmap(pt);
 195 }
 196
 197